Fetal transfusion of red blood cells for alloimmunization: validity of a published equation.

OBJECTIVE: To validate the equation published in 1990 by Leduc et al. for red blood cell fetal transfusion where fetoplacental blood volume (VO) = 100 ml/kg, then improve its precision. METHODS: We reviewed 101 fetal transfusions among 32 patients. We analyzed risk factors for an inaccurate estimation with uni- and multivariate analysis. We compared the obtained Leduc formula with three other published equations. RESULTS: Fetal weight and gestational age were risk factors for an inaccurate estimation of the final Hct. Before 32 weeks the estimation of VO was 120 ml/kg instead of 100 ml/kg. All formulae overestimated the mean expected Hct value. However, expected Hct estimated by Leduc's formula is the nearest of the observed final Hct. CONCLUSION: Leduc's equation seems to be accurate, but less so for the youngest fetuses. We propose an adapted formula VO according to gestational age and fetal weight estimation.

SOGC CLINICAL PRACTICE GUIDELINE: guidelines for the management of vasa previa.

OBJECTIVES: To describe the etiology of vasa previa and the risk factors and associated condition, to identify the various clinical presentations of vasa previa, to describe the ultrasound tools used in its diagnosis, and to describe the management of vasa previa. OUTCOMES: Reduction of perinatal mortality, short-term neonatal morbidity, long-term infant morbidity, and short-term and long-term maternal morbidity and mortality. EVIDENCE: Published literature on randomized trials prospective cohort studies, and selected retrospective cohort studies was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library, using appropriate controlled vocabulary (e.g., selected epidemiological studies comparing delivery by Caesarean section with vaginal delivery studies comparing outcomes when vasa previa is diagnosed antenatally vs.intrapartum) and key words (e.g. vasa previa). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline to October 1, 2008. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies,clinical practice guideline collections, clinical trial registries, and from national and international medical specialty societies. VALUES: The evidence collected was reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS: The benefit expected from this guideline is facilitation of optimal and uniform care for pregnancies complicated by vasa previa. SPONSORS: The Society of Obstetricians and Gynaecologists of Canada.

SOGC Clinical Practice Guidelines: Obesity in pregnancy. No. 239, February 2010.

OBJECTIVE: To review the evidence and provide recommendations for the counselling and management of obese parturients. OUTCOMES: OUTCOMES evaluated include the impact of maternal obesity on the provision of antenatal and intrapartum care, maternal morbidity and mortality, and perinatal morbidity and mortality. EVIDENCE: Literature was retrieved through searches of Statistics Canada, Medline, and The Cochrane Library on the impact of obesity in pregnancy on antepartum and intrapartum care, maternal morbidity and mortality, obstetrical anaesthesia, and perinatal morbidity and mortality. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to April 2009. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. VALUES: The evidence obtained was reviewed and evaluated by the Maternal Fetal Medicine and Clinical Practice Obstetric Committees of the SOGC under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS: Implementation of the recommendations in this guideline should increase recognition of the issues clinicians need to be aware of when managing obese women in pregnancy, improve communication and consultation amongst the obstetrical care team, and encourage federal and provincial agencies to educate Canadians about the values of entering pregnancy with as healthy a weight as possible.

SOGC clinical practice guideline: Vaginal delivery of breech presentation: no. 226, June 2009.

OBJECTIVES: To review the physiology of breech birth; to discern the risks and benefits of a trial of labour versus planned Caesarean section; and to recommend to obstetricians, family physicians, midwives, obstetrical nurses, anaesthesiologists, pediatricians, and other health care providers selection criteria, intrapartum management parameters, and delivery techniques for a trial of vaginal breech birth. OPTIONS: Trial of labour in an appropriate setting or delivery by pre-emptive Caesarean section for women with a singleton breech fetus at term. OUTCOMES: Reduced perinatal mortality, short-term neonatal morbidity, longterm infant morbidity, and short- and long-term maternal morbidity and mortality. EVIDENCE: Medline was searched for randomized trials, prospective cohort studies, and selected retrospective cohort studies comparing planned Caesarean section with a planned trial of labour; selected epidemiological studies comparing delivery by Caesarean section with vaginal breech delivery; and studies comparing long-term outcomes in breech infants born vaginally or by Caesarean section. Additional articles were identified through bibliography tracing up to June 1, 2008. VALUES: The evidence collected was reviewed by the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the criteria and classifications of the Canadian Task Force on Preventive Health Care. VALIDATION: This guideline was compared with the 2006 American College of Obstetrician's Committee Opinion on the mode of term singleton breech delivery and with the 2006 Royal College of Obstetrician and Gynaecologists Green Top Guideline: The Management of Breech Presentation. The document was reviewed by Canadian and International clinicians with particular expertise in breech vaginal delivery.

Predicting outcome in primary fetal hydrothorax.

OBJECTIVE: This study examines the role of serial ultrasound in predicting fetal outcomes based on progress, resolution or stability of pleural effusions in primary fetal hydrothorax (PFHT). METHODS: Records from consecutive cases of fetal pleural effusions referred to the fetal echocardiography unit over a 12-year period were reviewed. Study patients underwent thorough investigation to rule out secondary causes of pleural effusions. The clinical course was monitored with serial ultrasound studies every 2 weeks until delivery. Pleurocentesis and pleuroamniotic shunts were performed in select cases of PFHT. Fetal survival was the primary outcome variable. RESULTS: Eighteen of 44 patients referred for perinatal evaluation of fetal pleural effusions met the study criteria for PFHT. Diagnosis was made at 28 +/- 7 weeks and fetuses delivered at 35 +/- 3 weeks' gestational age. Overall survival was 78%. Effusion progression, greater effusion ratios, earlier gestational age at delivery, and lower Apgar scores at birth were associated with poor outcome. Conservative management was appropriate for most cases. CONCLUSIONS: Serial ultrasound studies to evaluate the clinical course of the pleural effusions are essential in the management of PFHT. Expectant management of stable and resolving effusions was appropriate in all cases.